That is the way mine is wired. All sound from the entertainment system comes from the Kenwood amp. I don't believe the TV has any speakers. The Unit is basically set up as a video monitor. All picture inputs come from the Sat receiver and Kenwood DVD with the exception of the smart card port.
To get picture and sound from AV4 run video to the TV AV4 and audio to Video 2 of the Kenwood or what ever open audio input port you chose.
Wayne & Kathy
05 Alpine 40FDQS #75330 Towing 24' car hauler, 2012 Spyder, 2003 Harley FatBoy